1 ////////////////////////////////////////////////////////////////////////////////
2 // MillScript: an Open Spice interpreter and batch website creation tool
3 // Copyright (C) 2001-2004 Open World Ltd
4 //
5 // This file is part of MillScript.
6 //
7 // MillScript is free software; you can redistribute it and/or modify it under
8 // the terms of the GNU General Public License as published by the Free
9 // Software Foundation; either version 2 of the License, or (at your option)
10 // any later version.
11 //
12 // MillScript is distributed in the hope that it will be useful, but WITHOUT
13 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 // more details.
16 //
17 // You should have received a copy of the GNU General Public License along with
18 // MillScript; if not, write to the Free Software Foundation, Inc., 59 Temple
19 // Place, Suite 330, Boston, MA 02111-1307 USA
20 ////////////////////////////////////////////////////////////////////////////////
21 package org.millscript.millscript.syntax;
22
23 import org.millscript.millscript.expr.ImportExpr;
24
25 /**
26 * This class implements <code>import</code> syntax. This is used to make
27 * another package available in the current packages environment.
28 *
29 * <p>
30 * <code>import [<expr> =] <expr></code>
31 * </p>
32 *
33 * <p>
34 * The right hand expression is the name of the package to import, which must be
35 * the full package name. The left hand side expression is optional, and allows
36 * you to specify a nickname for the package. If you don't specify a nickname,
37 * it will default to the part of the package name following the last period.
38 * </p>
39 *
40 * @see ImportExpr
41 */
42 public final class ImportSyntax extends PkgReaderSyntax {
43
44 /**
45 * @see org.millscript.millscript.syntax.PrefixSyntaxInterface#prefix(java.lang.String, org.millscript.millscript.syntax.Parser)
46 */
47 @Override
48 public ImportExpr prefix( final String sym, final Parser parser ) {
49 // Read a package name. This might actually be the nickname for the
50 // imported package.
51 String name = readPackageName( parser );
52 // Check to see if a nickname is specified.
53 if ( parser.tryRead( "=" ) ) {
54 // The name we just read is actually the nickame
55 String nn = name;
56 // So now read the actual package name we want to import.
57 name = readPackageName( parser );
58 // Return a new import expression for the specified package and
59 // nickname
60 return new ImportExpr( nn, name );
61 } else {
62 // Return a new import expression for the specified package, with
63 // the default nickname for the specified package
64 return new ImportExpr( nickname( name ), name );
65 }
66 }
67
68 }